Aston Martin diagnostic trouble code
P2779: Downshift or kickdown switch circuit fault
Use this reference to understand the recorded condition, confirm the available V8 Vantage or DB9 manual coverage, and follow the documented diagnostic checks before replacing parts.
- Code family
- Powertrain
- Vehicle system
- Transmission
- Manual coverage
- DB9
- Warning-lamp status
- DB9: Non-MIL
What Aston Martin code P2779 means
Downshift or kickdown switch circuit fault
DB9 preliminary diagnostic manual · section 2-316
Manufacturer fault-analysis procedure
Manual fault definition
P2779 Downshift Circuit (Kickdown)
Test sequence and decision path
1. Connect the WDS and confirm that P2779 is
logged.
2. Set the datalogger to monitor all throttle pedal
position sensors.
Switch on the ignition and datalogger. Fully open
and close the throttle several times. (Ensure that
the pedal reaches its fully open stop position).
Switch off datalogger and the ignition. Examine
the TPPS signals.
If the signals accurately follow pedal movement,
go to step 3.
If any signal is suspect, service the sensors or
wiring as necessary and repeat the test to ensure
that the problemis resolved.
3. Check the software level in th eTCM and PCMs
against that on the latest WDS disc.
If the vehicle software is not up to date, Reflash
the TCM and PCMs. Check that the DTC memory
is clear (apart from P1000). Repeat the throttle
position signal check to ensure that the problem
is resolved.
If the vehicle software is up to date, call Aston
Martin Technical Support.
Open the corresponding manual page for wiring diagrams and figures
logged.
2. Set the datalogger to monitor all throttle pedal
position sensors.
Switch on the ignition and datalogger. Fully open
and close the throttle several times. (Ensure that
the pedal reaches its fully open stop position).
Switch off datalogger and the ignition. Examine
the TPPS signals.
If the signals accurately follow pedal movement,
go to step 3.
If any signal is suspect, service the sensors or
wiring as necessary and repeat the test to ensure
that the problemis resolved.
3. Check the software level in th eTCM and PCMs
against that on the latest WDS disc.
If the vehicle software is not up to date, Reflash
the TCM and PCMs. Check that the DTC memory
is clear (apart from P1000). Repeat the throttle
position signal check to ensure that the problem
is resolved.
If the vehicle software is up to date, call Aston
Martin Technical Support.